Display panel and display device

ABSTRACT

A display panel comprises a first substrate, a second substrate disposed opposite to the first substrate, a liquid crystal layer disposed between the first and second substrates, and a pixel array disposed on the first substrate and including at least one pixel, which includes a first electrode layer, a second electrode layer and an insulation layer disposed between the first and second electrode layers. The second electrode layer has n electrode portions, the electrode portions are spaced from each other and disposed along a first direction, an electrode width of one of the electrode portions along the first direction is denoted by W (μm), the maximum width of a light-emitting area of the pixel along the first direction is denoted by Ax (μm), and the equation is satisfied as below: 
     
       
         
           
             
               
                 
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BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates to a display panel and a display device and, inparticular, to a display panel and a display device having a highertransmittance.

2. Related Art

With the progress of technologies, display devices have been widelyapplied to various kinds of fields. Especially, liquid crystal display(LCD) devices, having advantages such as compact structure, low powerconsumption, less weight and less radiation, gradually take the place ofcathode ray tube (CRT) display devices, and are widely applied tovarious electronic products, such as mobile phones, portable multimediadevices, notebooks, LCD TVs and LCD screens.

A conventional liquid crystal display (LCD) apparatus mainly includes anLCD panel and a backlight module disposed opposite to the LCD panel. TheLCD panel mainly includes a thin film transistor (TFT) substrate, acolor filter (CF) substrate and a liquid crystal layer disposed betweenthe two substrates. The CF substrate, the TFT substrate and the LC layercan form a plurality of pixel units disposed in an array. The backlightmodule emits the light passing through the LCD panel, and the pixelunits of the LCD panel can display images accordingly.

For the same luminance, a display panel with a higher transmittance cansave more energy for the display device. Therefore, the industry strivesto increase the transmittance of the display panel to save more energyand enhance the product competitiveness.

SUMMARY OF THE INVENTION

An objective of the invention is to provide a display panel and adisplay device having a higher transmittance so as to enhance theproduct competitiveness.

To achieve the above objective, a display panel according to theinvention comprises a first substrate, a second substrate disposedopposite to the first substrate, a liquid crystal layer disposed betweenthe first and second substrates, and a pixel array disposed on the firstsubstrate and including at least one pixel, which includes a firstelectrode layer, a second electrode layer and an insulation layerdisposed between the first and second electrode layers. The secondelectrode layer has n electrode portions, the electrode portions arespaced from each other and disposed in parallel along a first direction,an electrode width of one of the electrode portions along the firstdirection is denoted by W (μm), the maximum width of a light-emittingarea of the pixel along the first direction is denoted by Ax (μm), andthe equation is satisfied as below:

${{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} - 1} \leqq n \leqq {{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} + 1}$

wherein, n is a positive integer, and the unit of W and Ax is μm.

To achieve the above objective, a display device according to theinvention comprises a display panel. The display panel includes a firstsubstrate, a second substrate disposed opposite to the first substrate,a liquid crystal layer disposed between the first and second substrates,and a pixel array disposed on the first substrate and including at leastone pixel, which includes a first electrode layer, a second electrodelayer and an insulation layer disposed between the first and secondelectrode layers. The second electrode layer has n electrode portions,the electrode portions are spaced from each other and disposed inparallel along a first direction, an electrode width of one of theelectrode portions along the first direction is denoted by W (μm), themaximum width of a light-emitting area of the pixel along the firstdirection is denoted by Ax (μm), and the equation is satisfied as below:

${{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} - 1} \leqq n \leqq {{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} + 1}$

wherein, n is a positive integer, and the unit of W and Ax is μm.

In one embodiment, when a light passes through the pixel, the pixel hasa brightness distribution along the first direction, and the maximumwidth of the light-emitting area of the pixel along the first directionis the full width at half maximum (FWHM) of the brightness distribution.

In one embodiment, the pixel further includes a scan line, and the firstdirection is substantially parallel to the direction of the scan line.

In one embodiment, the second electrode layer further includes a firstconnecting portion, which surrounds the electrode portions and isconnected to the electrode portions.

In one embodiment, the second electrode layer further includes a secondconnecting portion, which is disposed on the opposite sides of theelectrode portions and connected to the electrode portions.

As mentioned above, in the display panel and display device of theinvention, the pixel array includes at least a pixel, and the insulationlayer of the pixel is disposed between the first electrode layer and thesecond electrode layer. The second electrode layer has n electrodeportions. The electrode portions are spaced from each other and disposedin parallel along the first direction, and the electrode width of one ofthe electrode portions along the first direction is denoted by W. Themaximum width of the light-emitting area of the pixel along the firstdirection is denoted by Ax. The equation is satisfied as below:

${{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} - 1} \leqq n \leqq {{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} + 1}$

wherein, n is a positive integer.

Accordingly, when the number (n) of the electrode portions of the secondelectrode layer, the electrode width (W) and the maximum width (Ax) ofthe light-emitting area of the pixel along the first direction complywith the above equation, the ratio of the dark area of the pixel can beminimized so as to obtain the maximum transmittance of the pixel.Therefore, the display panel and the display device of the invention canhave a higher transmittance and the product competitiveness can beenhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more fully understood from the detaileddescription and accompanying drawings, which are given for illustrationonly, and thus are not limitative of the present invention, and wherein:

FIG. 1A is a schematic diagram of a pixel of a display panel accordingto an embodiment of the invention;

FIG. 1B is a schematic sectional diagram taken along the line A-A inFIG. 1A;

FIG. 1C is a schematic diagram of a second electrode layer in FIG. 1B;

FIG. 2A is a schematic diagram showing the relative position between thesecond electrode layer and the dark regions of the pixel of the displaypanel in FIG. 1A;

FIG. 2B is a schematic diagram showing the relation between thebrightness and the second electrode layer of the pixel;

FIG. 2C is a schematic diagram showing the brightness distribution alongthe first direction of the pixel in FIG. 2A;

FIG. 2D is a schematic image diagram of the pixel of the display panelin FIG. 1A;

FIG. 3A is a schematic sectional diagram of a display panel according toanother embodiment of the invention;

FIG. 3B is a schematic diagram of the second electrode layer of thedisplay panel in FIG. 3A;

FIG. 3C is a schematic diagram of a pixel of a display panel accordingto another embodiment of the invention;

FIG. 3D is a schematic diagram of a pixel of a display panel accordingto another embodiment of the invention; and

FIG. 4 is a schematic diagram of a display device according to anembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be apparent from the following detaileddescription, which proceeds with reference to the accompanying drawings,wherein the same references relate to the same elements.

FIG. 1A is a schematic diagram of a pixel P of a display panel 1according to an embodiment of the invention, FIG. 1B is a schematicsectional diagram taken along the line A-A in FIG. 1A, and FIG. 1C is aschematic diagram of a second electrode layer 143 in FIG. 1B. Thedisplay panel 1 is, for example but not limited to, a fringe fieldswitching (FFS) display panel, or may be another kind of display panelwith a horizontal driving method. For helping understanding, FIG. lAjust shows two scan lines S, two data lines D, a pixel P, a firstelectrode layer 141 and a second electrode layer 143 of the displaypanel 1, and other elements are not shown. Besides, in this embodiment,a first direction X (horizontal direction), a second direction Y(vertical direction) and a third direction Z are shown in FIGS. 1A and1B, and they are perpendicular to one another. The first direction X issubstantially parallel to the direction of the scan line S, the seconddirection Y is substantially parallel to the direction of the data lineD, and the third direction Z is perpendicular to the first direction Xand the second direction Y.

As shown in FIGS. 1A to 1C, the display panel 1 includes a firstsubstrate 11, a second substrate 12 and a liquid crystal layer 13. Thefirst substrate 11 and the second substrate 12 are disposed oppositely,and the liquid crystal layer 13 is disposed between the first and secondsubstrates 11 and 12. Each of the first substrate 11 and the secondsubstrate 12 is made by a transparent material, and can be a glasssubstrate, a quartz substrate or a plastic substrate for example.

The display panel 1 further includes a pixel array, which is disposed onthe first substrate 11 and has at least a pixel P. In this embodiment,the pixel array includes a plurality of pixels, which are disposedbetween the first and second substrates 11 and 12 and in an array alongthe first and second directions X and Y. Besides, the display panel 1can further include a plurality of scan lines S and a plurality of datalines D, and the scan lines S and the data lines D cross each other todefine the area of the pixel array.

As shown in FIG. 1B, the pixel P includes a first electrode layer 141,an insulation layer 142 and a second electrode layer 143. In thisembodiment, the first electrode layer 141, the insulation layer 142 andthe second electrode layer 143 are disposed on the side of the firstsubstrate 11 facing the second substrate 12 sequentially from bottom totop. The data lines D and the first electrode layers 141 are disposed onthe first substrate 11. Herein, the first electrode layer 141 isdisposed within the two adjacent data lines D and within the twoadjacent scan lines S.

The insulation layer 142 covers the first electrode layer 141 and thedata line D, and the second electrode layer 143 is disposed on theinsulation layer 142. Herein, the insulation layer 142 is disposedbetween the first electrode layer 141 (with the data line D) and thesecond electrode layer 143 to separate the first electrode layer 141,the data line D and the second electrode layer 143 for avoiding a shortcircuit. The material of the insulation layer 142 may include SiOx, SiNxor the like, but the invention is not limited thereto. Each of the firstand second electrode layers 141 and 143 is a transparent conductivelayer, and the material thereof may include indium tin oxide (ITO) forexample. In this embodiment, the first electrode layer is a pixelelectrode and electrically connected to the data line D, and the secondelector delayer 143 is a common electrode. In other embodiments,however, the first electrode layer 141 can be a common electrode whilethe second electrode layer 143 is a pixel electrode.

The second electrode layer 143 includes n electrode portions 1431 (n isa positive integer), and further includes a first connecting portion1432 that surrounds the electrode portions 1431 and is connected to theelectrode portions 1431. Herein as shown in FIG. 1C, the number (n) ofthe electrode portions 1431 is 3, and the first connecting portion 1432is disposed around and connected to the three electrode portions 1431.The electrode portions 1431 are spaced from each other and disposed inparallel along the first direction X. The electrode width of one of theelectrode portions of the second electrode layer 143 is denoted by W.The electrode width W has the range complying with 1 μm≦W≦5 μm forexample and with 1.5 μm≦W≦3.5 μm favorably.

As shown in FIG. 1B, the display panel 1 can further include a blackmatrix BM and a filter layer (not shown). The black matrix BM isdisposed on the first substrate 11 or the second substrate 12 andcorresponding to the data lines D. The black matrix BM is made by opaquematerial, which includes metal (e.g. Cr, chromium oxide, or Cr—O—Ncompound) or resin for example. In this embodiment, the black matrix BMis disposed on the side of the second substrate 12 facing the firstsubstrate 11 and over the data line D along the third direction Z.Accordingly, the black matrix BM covers the data lines D in a top viewof the display panel 1.

The filter layer (not shown) is disposed on the side of the secondsubstrate 12 and the black matrix BM facing the first substrate 11 ordisposed on the first substrate 11. Since the black matrix BM is opaque,a corresponding opaque area can be formed on the second substrate 12 soas to define a transparent area. Therefore, when the light passesthrough the pixel P, the pixel P will have a light-emitting area (thearea permeable to light). The black matrix BM includes a plurality oflight-blocking segments, and at least one light-blocking segment isdisposed between two adjacent filter portions of the filter layer. Inthis embodiment, the black matrix BM and the filter layer are bothdisposed on the second substrate 12. In other embodiments, however, theblack matrix BM or the filter layer can be disposed on the firstsubstrate 11 for making a BOA (BM on array) substrate or a COA (colorfilter on array) substrate. To be noted, the above-mentioned structureof the substrate is just for example but not for limiting the scope ofthe invention. Moreover, the display panel 1 can further include aprotection layer (e.g. over-coating, not shown), which can cover theblack matrix BM and the filter layer. The protection layer can includephotoresist material, resin material or inorganic material (e.g.SiOx/SiOx), protecting the black matrix BM and the filter layer frombeing damaged during the subsequent processes.

When the scan lines S of the display panel 1 receive a scan signalsequentially, the TFT (not shown) corresponding to each of the scanlines S can be enabled. Then, the data signals can be transmitted to thecorresponding pixel electrodes through the data lines D and the displaypanel 1 can display images accordingly. In this embodiment, thegray-level voltage can be transmitted to the first electrode layer 141(pixel electrode) of each of the pixels P through each of the data linesD, and an electric filed can be thus formed between the first electrodelayer 141 and the second electrode layer 143 (common electrode) to drivethe LC molecules of the LC layer 13 to rotate on the plane that is inthe first and second directions X and Y. Therefore, the light can bemodulated and the display panel 1 can display images accordingly.

However, when the electric field is formed between the first electrodelayer 141 and the second electrode layer 143 (common electrode) to drivethe LC molecules to rotate, the horizontal rotation of the LC moleculesin the central area of each of the electrode portions 1431 and in thearea between the adjacent electrode portions 1431 is limited because ofthe electric field distribution (denoted by the dotted lines in FIG. 1B)in the said areas. Hence, when the light passes through the pixel P, thedark regions will be generated in the central area of each of theelectrode portions 1431 and in the area between the adjacent electrodeportions 1431, reducing the transmittance of the display panel 1. So,decreasing the said area of the dark regions indicates the increment ofthe transmittance of the display panel 1, and the increment of thetransmittance indicates the energy can be saved and the productcompetitiveness can be enhanced.

Accordingly, how to minimize the area of the dark regions to increasethe transmittance of the display panel 1 will be illustrated as below byreferring to FIGS. 2A to 2D. FIG. 2A is a schematic diagram showing therelative position between the second electrode layer 143 and the darkregions of the pixel P of the display panel 1 in FIG. 1A, FIG. 2B is aschematic diagram showing the relation between the brightness (e.g.luminance) and the second electrode layer 143 of the pixel P, FIG. 2C isa schematic diagram showing the brightness distribution along the firstdirection X of the pixel P in FIG. 2A, and FIG. 2D is a schematic imagediagram of the pixel P of the display panel 1 in FIG. 1A. Herein asshown in FIG. 2D, when the light passes through the pixel P, the pixel Pwill have a light-emitting area, the maximum width of which along thefirst direction X is denoted by Ax (e.g. 10 μm≦Ax≦250 μm) and themaximum width of which along the second direction Y is denoted by Ay(e.g. Ay≈3Ax). So, the total area of the light-emitting area is denotedby the product of Ax and Ay. Moreover, the dotted lines in FIG. 2Adenote the dark regions generated when the light passes through thepixel P, and the dark regions include straight dark regions D1 andtriangular dark regions D2. The wave trough of the brightness curve inFIG. 2B denotes the location of the dark region. Furthermore, as shownin FIG. 2C, the maximum width Ax of the light-emitting area along thefirst direction X is defined as the full width at half maximum (FWHM) ofthe brightness distribution curve of the pixel P along the firstdirection X.

As shown in FIG. 2A, when the light passes through the dark regions ofthe pixel P, the number of the straight dark regions D1 is 2n+1 (that is7 for n=3 here) since the number of the electrode portions 1431 of thesecond electrode layer 143 in this embodiment is 3 (n). Besides, for theactual layout of the second electrode layer 143, the connection portions(i.e. the upper and lower edges of the pixel P along the seconddirection Y) of two sides of the electrode portion 1431 and the firstconnecting portion 1432 can have a turning each, and a triangular darkregion D2 will occur at the turning, between the two turnings andbetween the turning and the first connecting portion 1432, so the numberof the triangular dark regions is 2*(2n+1) (i.e. 2*7=14 in thisembodiment). From FIG. 2A, when the total area of the straight andtriangular dark regions D1 and D2 is minimized relative to the totalarea of the light-emitting area, the transmittance of the pixel P can bemaximized.

As shown in FIG. 2B, by taking the left side electrode portion 1431 asan example, the total brightness energy of the electrode portion 1431 isdenoted by the rectangular area Z1 bounded by the solid line (i.e. theintegral of the brightness distribution curve under the conditionwithout any dark region), and the brightness loss due to the darkregions is approximately denoted by the triangular area Z2 bounded bythe solid line (i.e. the integral of the indented portion of thebrightness distribution curve). The triangular area Z2 representing thebrightness loss can be equalized as a rectangular area Z3 with the sameheight as the rectangular area Z1 (i.e. Z2 is equivalent to the areaZ3), so the ratio of the triangular area Z2 (the brightness loss) to thetotal brightness energy (without any dark region) of the electrodeportion 1431 is equivalent to the ratio (R) of the width of the area Z3(the width of the dark region) to the width of the area Z1 (the width ofthe electrode portion 1431). By the actual measuring and calculation,the ratio R is about 0.1 (R≈0.1, that is to say the width of the area Z3is about 0.1 times the width of the area Z1). In other embodiments, theratio R can be 0.05˜0.5(0.05≦R≦0.5).

Hence, the transparent area T of the pixel P can be obtained bysubtracting the area of the dark regions (including the triangular darkregions D2 and the straight dark regions D1) from the area of thelight-emitting area, as the following equation:

$\begin{matrix}{T = {{{Ax} \times {Ay}} - {2 \times ( {{2n} + 1} ) \times \frac{1}{2} \times ( \frac{Ax}{( {{2n} + 1} )} )^{2}} -}} \\{{( {{2n} + 1} ) \times W \times R \times {Ay}}} \\{= {{{Ax} \times {Ay}} - \frac{{Ax}^{2}}{( {{2n} + 1} )} - {( {{2n} + 1} ) \times W \times R \times {Ay}}}}\end{matrix}$

To obtain the maximum, the differential is derived from the equation asbelow:

$\frac{\partial T}{\partial n} = {\frac{\partial T}{\partial( {{2n} + 1} )} \times \frac{\partial( {{2n} + 1} )}{\partial n}}$

Then, the equation can be obtained as below:

T′=(2n+1)⁻² ×Ax ²×2−W×R×Ay×2

When T=0, the maximum exists, so the equation becomes:

$n = {\frac{1}{2} \times ( {\sqrt{\frac{{Ax}^{2}}{W \times R \times {Ay}}} - 1} )}$

By substituting Ay≈3Ax into the above equation, the equation becomes:

$n = {\frac{1}{2} \times ( {\sqrt{\frac{Ax}{3 \times W \times R}} - 1} )}$

Again, by substituting R≈0.1 into the above equation, the equationbecomes:

$n = {\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )}$

Accordingly, the optimized n (positive integer) in this embodiment willcomply with the following equation:

${{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} - 1} \leqq n \leqq {{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} + 1}$

In this condition, the ratio of the area of the dark regions to the areaof the light-emitting area of the pixel P can be minimized so as toobtain the maximum transmittance of the pixel P, and therefore thedisplay panel 1 is configured with a higher transmittance and theproduct competitiveness can be increased.

FIG. 3A is a schematic sectional diagram of a display panel 1 aaccording to another embodiment of the invention, FIG. 3B is a schematicdiagram of the second electrode layer 143 a of the display panel 1 a inFIG. 3A, FIG. 3C is a schematic diagram of a pixel Pb of a display panel1 b according to another embodiment of the invention, and FIG. 3D is aschematic diagram of a pixel Pc of a display panel 1 c according toanother embodiment of the invention.

As shown in FIG. 3A, mainly different from the display panel 1 in FIG.1B, the first electrode layer 141 of the display panel 1 a is a commonelectrode while the second electrode layer 143 a is a pixel electrode.As shown in FIG. 3B, the second electrode layer 143 a includes threeelectrode portions 1431 and a second connecting portion 1433, which isdisposed on the opposite sides of the electrode portions 1431 andconnected to the electrode portions 1431. As shown in FIG. 3A, the dataline D is disposed on the first substrate 11, and the pixel Pa furtherincludes another insulation layer 145 covering the data line D, so thatthe first electrode layer 141 is disposed between the insulation layer142 and the insulation layer 145.

As shown in FIG. 3C, mainly different from the display panel 1 in FIG.1A, the second direction Y of the display panel 1 b is substantiallyparallel to the direction of the data line D but the first direction Xand the second direction Y are not perpendicular to each other and forman obtuse angle, so that the pixel Pb is about a parallelogram. In otherwords, the scan lines S and the data lines D of the display panel 1 bstill cross each other but they are not perpendicular to each other andform an obtuse angle, so that each of the pixel Pb, the first electrodelayer 141 b and the second electrode layer 143 b substantially has ashape of parallelogram.

As shown in FIG. 3D, mainly different from the display panel 1 in FIG.1A, the data line D of the pixel Pc of the display panel 1 c has aturning. Therefore, the pixel Pc is not a parallelogram but has aturning corresponding to the turning of the data line. Besides, theelectrode portion 1431 and the first connecting portion 1432 of thesecond electrode layer 143 c have turnings corresponding to the pixelPc, and the first electrode layer 141 c also has a turningcorrespondingly.

The other technical features of the display panels 1 a, 1 b, 1 c can becomprehended by referring to the same elements of the display panel 1,and therefore they are not described here for conciseness.

FIG. 4 is a schematic diagram of a display device 2 according to anembodiment of the invention.

As shown in FIG. 4, the display device 2 includes a display panel 3 anda backlight module 4 disposed opposite to the display panel 3. Thedisplay panel 3 can be anyone of the display panels 1, 1 a, 1 b and 1 cand is not described here for conciseness. When the backlight module 4emits the light passing through the display panel 3, the pixels of thedisplay panel 3 can display colors and images accordingly.

Summarily, in the display panel and display device of the invention, thepixel array includes at least a pixel, and the insulation layer of thepixel is disposed between the first electrode layer and the secondelectrode layer. The second electrode layer has n electrode portions.The electrode portions are spaced from each other and disposed inparallel along the first direction, and the electrode width of one ofthe electrode portions along the first direction is denoted by W. Themaximum width of the light-emitting area of the pixel along the firstdirection is denoted by Ax. The equation is satisfied as below:

wherein, n is

${{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} - 1} \leqq n \leqq {{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} + 1}$

a positive integer.

Accordingly, when the number (n) of the electrode portions of the secondelectrode layer, the electrode width (W) and the maximum width (Ax) ofthe light-emitting area of the pixel along the first direction complywith the above equation, the ratio of the area of the dark regions tothe area of the light-emitting area of the pixel can be minimized so asto obtain the maximum transmittance of the pixel. Therefore, the displaypanel and the display device of the invention can have a highertransmittance and the product competitiveness can be enhanced.

Although the invention has been described with reference to specificembodiments, this description is not meant to be construed in a limitingsense. Various modifications of the disclosed embodiments, as well asalternative embodiments, will be apparent to persons skilled in the art.It is, therefore, contemplated that the appended claims will cover allmodifications that fall within the true scope of the invention.

What is claimed is:
 1. A display panel, comprising: a first substrateand a second substrate disposed opposite to the first substrate; aliquid crystal layer disposed between the first and second substrates;and a pixel array disposed on the first substrate and including at leastone pixel, which includes a first electrode layer, a second electrodelayer and an insulation layer disposed between the first and secondelectrode layers, wherein the second electrode layer has n electrodeportions, the electrode portions are spaced from each other and disposedalong a first direction, an electrode width of one of the electrodeportions along the first direction is denoted by W (μm), the maximumwidth of a light-emitting area of the pixel along the first direction isdenoted by Ax (μm), and the equation is satisfied as below:${{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} - 1} \leqq n \leqq {{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} + 1}$wherein, n is a positive integer, and the unit of W and Ax is μm.
 2. Thedisplay panel as recited in claim 1, wherein when a light passes throughthe pixel, the pixel has a brightness distribution along the firstdirection, and the maximum width of the light-emitting area of the pixelalong the first direction is the full width at half maximum (FWHM) ofthe brightness distribution.
 3. The display panel as recited in claim 1,wherein the pixel further includes a scan line, and the first directionis substantially parallel to the direction of the scan line.
 4. Thedisplay panel as recited in claim 1, wherein the second electrode layerfurther includes a first connecting portion, which surrounds theelectrode portions and is connected to the electrode portions.
 5. Thedisplay panel as recited in claim 1, wherein the second electrode layerfurther includes a second connecting portion, which is disposed on theopposite sides of the electrode portions and connected to the electrodeportions.
 6. A display device, comprising: a display panel including afirst substrate, a second substrate disposed opposite to the firstsubstrate, a liquid crystal layer disposed between the first and secondsubstrates, and a pixel array disposed on the first substrate andincluding at least one pixel, which includes a first electrode layer, asecond electrode layer and an insulation layer disposed between thefirst and second electrode layers, wherein the second electrode layerhas n electrode portions, the electrode portions are spaced from eachother and disposed along a first direction, an electrode width of one ofthe electrode portions along the first direction is denoted by W (μm),the maximum width of a light-emitting area of the pixel along the firstdirection is denoted by Ax (μm), and the equation is satisfied as below:${{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} - 1} \leqq n \leqq {{\frac{1}{2} \times ( {\sqrt{\frac{10 \times {Ax}}{3 \times W}} - 1} )} + 1}$wherein, n is a positive integer, and the unit of W and Ax is μm.
 7. Thedisplay device as recited in claim 6, wherein when a light passesthrough the pixel, the pixel has a brightness distribution along thefirst direction, and the maximum width of the light-emitting area of thepixel along the first direction is the full width at half maximum (FWHM)of the brightness distribution.
 8. The display device as recited inclaim 6, wherein the pixel further includes a scan line, and the firstdirection is substantially parallel to the direction of the scan line.9. The display device as recited in claim 6, wherein the secondelectrode layer further includes a first connecting portion, whichsurrounds the electrode portions and is connected to the electrodeportions.
 10. The display device as recited in claim 6, wherein thesecond electrode layer further includes a second connecting portion,which is disposed on the opposite sides of the electrode portions andconnected to the electrode portions.